Difference: GCNCIRCULAR21675 ( vs. 1)

D. Xu (NAO/CAS), B. Li, H.B. Zhao, G.T. Zhaori, H. Lu, R.Q. Hong, L.F. Hu (PMO/CAS), H.X. Feng, Z.P. Zhu, T.M. Zhang, X. Zhou (NAO/CAS), J.Z. Liu, H.B. Niu, Y. Zhang, X. Zhang, G.X. Pu, S.G. Ma,T.Z. Yang, F.F. Song (XAO/CAS), J. Mao, J.M. Bai (YNAO/CAS) report on behalf of the Gravitational Wave Follow-Up Network by NAO-PMO-XAO-YNAO in China (GWFUNC):

We have performed tiled observations of LIGO/Virgo G298936 (LVC, GCN 21656) using the 1-m Chinese Near Earth Object Survey Telescope (CNEOST) at Xuyi, Jiangsu, China.

CNEOST has a FOV of 3.0x3.0 deg^2, and carried out observations during 17:46:32 - 20:45:48 UT on 2017-08-23 in the Sloan i-filter. In total, 387 deg^2 is covered on the skymap with the highest localization probability in the north hemisphere. During the observations, the typical 5\sigma limit is ~19.8 mag.

Preliminary analysis reveals an optical transient (OT), named as GWFUNC-17ure, at the coordinates

RA (J2000) = 03:40:39.45 DEC (J2000) = +40:33:22.90

with m(i)~19.2 at 18:54:42 UT on 2017-08-23, apparently localized in its host galaxy SDSS J034039.45+403322.6 that has m(g)=20.32, m(r)=19.53, m(i)=19.14, as well as a PhotZ=0.12+/-0.04 (corresponding to D_L ~ 577 +/- 200 Mpc).

Spectral observations of the above OT is encouraged.

-- DeepChatterjee - 25 Aug 2017